LONDON (Reuters) - Greek Finance Minister Yanis Varoufakis will tell major investors and bankers later on Monday that Greece will be able to service its debt with no damage done to private investors, a source with knowledge of the matter said.

The source said Varoufakis planned to meet about 100 banks and financial institutions at an event later on Monday.

"We will be able to service the Greek debt on terms that will have no detrimental impact on, especially private, bond holders," said the source, who spoke on condition of anonymity because of the sensitivity of the matter.

"The message will be that we are very open to investment, that people should listen to the finance minister, who's got absolute confidence of the prime minister, rather than other noises from any other direction," the source said.

Varoufakis, wearing a bright blue untucked shirt and a black jacket with no tie, had a 45-minute meeting over coffee with besuited British finance minister George Osborne in Downing Street on Monday.

After the meeting, Varoufakis left Downing Street without public comment.

Reporting by William James, writing by Guy Faulconbridge and David Milliken; Editing by Larry King